Question

How can we separate citric acid from hand soap and/or how do you calculate the amount of citric acid in hand soap?

Answer 1

As we know around 4 grams of citric acid should bring down the pH of one Kg of soap paste by around 5. This is highly dependent upon how much water is in your water paste. Because citric acid is very good acidic. It’s very easy to add too much citric acid, especially with small batches. We should add it little by little. If you are adding too much then it will first begin to make the soap look cloudy, and will later cause it to separate. You should check the pH between the each additions of citric acid, but we should know that pH readings may be inaccurate.

We were worried that, my soap was too alkaline because it was causing the skin irritation already. In the case of an irritating soap, We should make a dilute solution of citric acid and use it during the second dilution of my soap to slowly lower the pH slightly.

If you see things are starting to separate, stop adding the citric acid solution and allow the soap to sit for awhile before trying to combine everything back together again. If you need then you can finish diluting the soap with more amount of distilled water.